@article{10_21136_CMJ_2019_0352_18,
     author = {Wei, Changguo and Zhao, Xiangmei and Liu, Shudong},
     title = {Pseudometrics on {Ext-semigroups}},
     journal = {Czechoslovak Mathematical Journal},
     pages = {435--451},
     publisher = {mathdoc},
     volume = {70},
     number = {2},
     year = {2020},
     doi = {10.21136/CMJ.2019.0352-18},
     mrnumber = {4111852},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.2019.0352-18/}
}